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Steel is the most commonly used material for long-span structure. But how to protect a steel structure from corrosion? Painted steel building do not last long while stainless steel and aluminum are prohibitively expensive. LF spatial structure are built with maintain-free durable materials which are galvanized. The structure doesn’t need maintain once it is completed to lower lifetime price and reduce the risk happened during maintain specially for huge building with high rise. LF also provide another economical option of special paint finish which doesn’t need to maintain more than 15 years.


  

Criteria

Hot-dip galvanizing

Electro-galvanizing

Paint

Corrosion

Protection

Cathodic & barrier

Cathodic & barrier

Barrier

Coverage on corners/edges

Uniform coverage including corners, edges, and threads

Maybe thin or no coating in difficult to access areas

Holidays and pin holes possible, coating tends to thin on edges/corners

Coating thickness

1.7 to 3.4 mils

0.2 mils

1-3 mils

Bond strength

3,600 psi

300-600 psi

300-600 psi

Hardness

Alloy layer harder than base steel, with DPN hardness ranging from 179-250

50% as hard as base steel

Soft & susceptible to handling damage

Temperature range

-100 C to 200 C

-100 C to 200 C

Dependent on formulation

Paintability

Can be painted

Can be painted

n/a

Application

Shop

Shop

Shop or field

Conditions

Independent of weather

Independent of weather

Temperature & humidity restrictions

Procedure

After cleaning with series of chemicals, dipped in molten zinc bath, then spun to remove excess zinc

Clean steel, immerse parts in a zinc acid bath, and drive current through bath

Clean steel rinse, dry, brush or spray multiple coats

Performance:

Time to first maintenance

50+ years

10+ years

10-20 years

Suitability

Outdoor and indoor, applications

Outdoor sparingly, indoor main applications

Outdoor and indoor applications